Solid-state imaging device and electronic device

ABSTRACT

In a solid-state imaging device, a material forming an underfill part is prevented from flowing toward a side of a pixel region, shortening of a distance between an end portion of an opening of a substrate and the pixel region is enabled, and miniaturization is promoted. The device includes: an imaging element having a pixel region including a large number of pixels on one plate surface of a semiconductor substrate; a substrate provided on the surface side with respect to the imaging element and having an opening for passing light to be received by the pixel region; and an underfill part including a cured fluid and covering a connection part that electrically connects the imaging element and the substrate, in which the substrate has a groove for guiding the fluid forming the underfill part in a direction away from the surface of the imaging element.

TECHNICAL FIELD

The present technology relates to a solid-state imaging device and anelectronic device.

BACKGROUND ART

Some solid-state imaging devices having an image sensor as a solid-stateimaging element have a so-called flip-chip structure in which an imagesensor and a substrate are electrically connected via a connection partsuch as a bump which is a protruding terminal. The substrate is, forexample, a substrate that is formed including a material such as anorganic material or ceramics, is provided with a wiring layer,electrodes, or the like, and has an opening for passing light to bereceived by the image sensor. A translucent member such as glass isprovided on the side of the substrate opposite to the image sensor sideso as to cover the opening of the substrate, and a package structure inwhich a hollow portion is formed on the light receiving surface side ofthe image sensor is configured.

In the flip-chip structure, an underfill part is provided between thesubstrate and the image sensor for the purpose of protecting orreinforcing the connection part such as a bump. The underfill part is,for example, a portion formed by curing a paste-like or liquid resinwhich is a fluid. Some underfill parts are of a capillary flow type(capillary underfill) formed by causing a liquid resin having arelatively low viscosity to flow by using a capillary phenomenon.

In the flip-chip structure having an underfill part, there is a problemthat a liquid resin before curing (hereinafter referred to as “underfillmaterial”) forming the underfill part reaches a pixel region which isthe light receiving region of the image sensor, and adversely affectsthe characteristics of the image sensor. A technology for such a problemis disclosed, for example, in Patent Document 1.

Patent Document 1 discloses a technology of, in order to prevent anunderfill material from reaching a pixel region of an image sensor,securing a dimension of a distance from an opening end portion of anopening of a substrate and an end portion of the pixel region of theimage sensor on the basis of a dimension of a gap between plate surfacesof the substrate and the image sensor. Furthermore, Patent Document 1discloses a configuration in which, on the image sensor, an embankmentportion or a groove is provided in a portion between the opening endportion of the opening of the substrate and the pixel region, that is, aportion in front of the pixel region in the flow of the underfillmaterial, so that the flow of the resin to the pixel region side isstopped.

CITATION LIST Patent Document

-   Patent Document 1: Japanese Patent Application Laid-Open No.    2002-124654

SUMMARY OF THE INVENTION Problems to be Solved by the Invention

Certainly, according to the conventional technology as disclosed inPatent Document 1, it is conceivable that an underfill material can beprevented from reaching a pixel region. However, according to theconventional technology, there are problems as below.

First, as described above, the technology of securing the dimension ofthe distance between the opening end portion of the opening of thesubstrate and the end portion of the pixel region of the image sensor isbased on the premise that the underfill material expands toward thepixel region, and is to secure an area that allows the expansion.Therefore, such a technology hinders the miniaturization of the imagesensor and the package structure. Furthermore, as described above, theconfiguration in which the embankment portion or the groove is providedin the portion in front of the pixel region on the image sensor alsohinders miniaturization because it is necessary to secure a space forproviding the embankment portion or the groove in the image sensor.

In recent years, image sensors have tended to be Staked Die, andtherefore, miniaturization of image sensor chips has been advanced. Theminiaturization of the image sensor contributes to cost reduction.However, according to the prior art, it is difficult to bring thedistance between the opening end portion of the opening of the substrateand the pixel region close from the viewpoint of preventing theunderfill material from reaching the pixel region, which hinders theminiaturization of the image sensor.

An object of the present technology is to provide a solid-state imagingdevice and an electronic device capable of preventing a material formingan underfill part from flowing toward a side of a pixel region of asolid-state imaging element, shortening a distance between an openingend portion of an opening of a substrate and the pixel region, andpromoting miniaturization of the solid-state imaging element and thedevice.

Solutions to Problems

A solid-state imaging device according to the present technologyincludes: a solid-state imaging element having a pixel region which is alight receiving region including a large number of pixels on a surfaceside which is one plate surface of a semiconductor substrate; asubstrate provided on the surface side with respect to the solid-stateimaging element and having an opening for passing light to be receivedby the pixel region; and an underfill part formed including a curedfluid and covering a connection part that electrically connects thesolid-state imaging element and the substrate, in which the substratehas a groove for guiding the fluid forming the underfill part in adirection away from the surface of the solid-state imaging element, on asurface portion forming the opening.

Another aspect of the solid-state imaging device according to thepresent technology is the solid-state imaging device in which the grooveis formed by a semi-cylindrical concave curved surface.

Another aspect of the solid-state imaging device according to thepresent technology is the solid-state imaging device in which the grooveis inclined in a direction in which an opening width of the opening isnarrowed from a side of the solid-state imaging element to the oppositeside with respect to a plate thickness direction of the substrate.

Another aspect of the solid-state imaging device according to thepresent technology is the solid-state imaging device in which the grooveis inclined in a direction in which an opening width of the opening iswidened from a side of the solid-state imaging element to the oppositeside with respect to a plate thickness direction of the substrate.

An electronic device according to the present technology includes asolid-state imaging device, the solid-state imaging device including: asolid-state imaging element having a pixel region which is a lightreceiving region including a large number of pixels on a surface sidewhich is one plate surface of a semiconductor substrate; a substrateprovided on the surface side with respect to the solid-state imagingelement and having an opening for passing light to be received by thepixel region; and an underfill part formed including a cured fluid andcovering a connection part that electrically connects the solid-stateimaging element and the substrate, in which the substrate has a groovefor guiding the fluid forming the underfill part in a direction awayfrom the surface of the solid-state imaging element, on a surfaceportion forming the opening.

Effects of the Invention

According to the present technology, it is possible to prevent amaterial forming an underfill part from flowing toward a side of a pixelregion of a solid-state imaging element, shorten a distance between anopening end portion of an opening of a substrate and the pixel region,and promote miniaturization of the solid-state imaging element and thedevice.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view showing a configuration of a solid-stateimaging device according to a first embodiment of the presenttechnology.

FIG. 2 is a plan view showing the configuration of the solid-stateimaging device according to the first embodiment of the presenttechnology.

FIG. 3 is an end view of the A-A line cut portion in FIG. 2.

FIG. 4 is an end view of the B-B line cut portion in FIG. 2.

FIG. 5 is a perspective view showing a configuration of a substrateaccording to the first embodiment of the present technology.

FIG. 6 is a plan view showing the configuration of the substrateaccording to the first embodiment of the present technology.

FIG. 7 is a cross-sectional view taken along the line C-C in FIG. 6.

FIG. 8 is a cross-sectional view taken along the line D-D in FIG. 6.

FIG. 9 is an explanatory diagram of a method of manufacturing thesolid-state imaging device according to the first embodiment of thepresent technology.

FIG. 10 is an explanatory diagram of a method of manufacturing thesolid-state imaging device according to the first embodiment of thepresent technology.

FIG. 11 is an explanatory diagram of a method of manufacturing thesolid-state imaging device according to the first embodiment of thepresent technology.

FIG. 12 is an explanatory diagram of a phenomenon that occurs in aconfiguration of a comparative example for the present technology.

FIG. 13 is a cross-sectional view of a side end face showing aconfiguration of a solid-state imaging device according to a secondembodiment of the present technology.

FIG. 14 is a plan view showing the configuration of the substrateaccording to the second embodiment of the present technology.

FIG. 15 is a cross-sectional view taken along the line E-E in FIG. 14.

FIG. 16 is a cross-sectional view of a side end face showing aconfiguration of a solid-state imaging device according to a thirdembodiment of the present technology.

FIG. 17 is a plan view showing the configuration of the substrateaccording to the third embodiment of the present technology.

FIG. 18 is a cross-sectional view taken along the line F-F in FIG. 17.

FIG. 19 is an explanatory diagram of action and effect in thesolid-state imaging device according to the third embodiment of thepresent technology.

FIG. 20 is a diagram showing a modification of a groove of a substrateaccording to the embodiment of the present technology.

FIG. 21 is a diagram showing a modification of a groove of a substrateaccording to the embodiment of the present technology.

FIG. 22 is a block diagram showing a configuration example of anelectronic device provided with a solid-state imaging device accordingto the embodiment of the present technology.

MODE FOR CARRYING OUT THE INVENTION

The present technology is intended to devise the shape of a surfaceforming an opening of a substrate in a configuration in which anunderfill part covering a connection part that electrically connects asolid-state imaging element and the substrate having an opening forpassing light to be received by the solid-state imaging element, tosuppress a fluid forming the underfill part from flowing toward a pixelregion of the solid-state imaging element.

Embodiments for implementing the present technology (hereinafter,referred to as “embodiments”) will be described below with reference tothe drawings. Note that the embodiments will be described in thefollowing order.

1. Configuration example of solid-state imaging device according to thefirst embodiment

2. Manufacturing method of solid-state imaging device according to thefirst embodiment

3. Configuration example of solid-state imaging device according to thesecond embodiment

4. Configuration example of solid-state imaging device according to thethird embodiment

5. Modification of groove of substrate

6. Configuration example of electronic device

<Configuration Example of Solid-State Imaging Device According to theFirst Embodiment>

A configuration example of a solid-state imaging device 1 according to afirst embodiment of the present technology will be described withreference to FIGS. 1 to 8. As shown in FIG. 1, the solid-state imagingdevice 1 includes an image sensor 2 as a solid-state imaging element, asubstrate 3 on which an opening 4 for passing light to be received bythe image sensor 2 is formed, and a glass 5 as a translucent membersupported on the substrate 3. Furthermore, the solid-state imagingdevice 1 includes a metal bump 6 which is a connection part thatelectrically connects the image sensor 2 and the substrate 3, and anunderfill part 7 covering the metal bump 6. Note that, in FIGS. 1 and 2,the glass 5 is shown by a chain double-dashed line for convenience.

The solid-state imaging device 1 has a so-called flip-chip structure inwhich the image sensor 2 and the substrate 3 are electrically connectedvia a plurality of metal bumps 6. In the solid-state imaging device 1,the glass 5 is mounted so as to cover the opening 4 on the side oppositeto the image sensor 2 of the substrate 3, and the solid-state imagingdevice 1 has a package structure in which a cavity 8 which is a closedspace including an internal space of the opening 4 of the substrate 3 isprovided between the image sensor 2 and the glass 5.

The image sensor 2 includes a silicon semiconductor substrate includingsilicon (Si), which is an example of a semiconductor, and one platesurface side (upper side in FIG. 1) of the semiconductor substrate is alight receiving side. The image sensor 2 is a rectangular plate-shapedchip, and a plate surface on the light receiving side is a front surface2 a, and a plate surface on the opposite side is a back surface 2 b. Theimage sensor 2 according to the present embodiment is a complementarymetal oxide semiconductor (CMOS) type image sensor. However, the imagesensor 2 may be a charge coupled device (CCD) type image sensor.

Most of the image sensor 2 is configured by a semiconductor substrate,and an image sensor element is formed on the surface 2 a side. The imagesensor 2 has a pixel region 2 c as a light receiving part on the surface2 a side, which is a light receiving region including a large number ofpixels formed in a predetermined array such as a Bayer array, and aregion around the pixel region 2 c is a peripheral region. The pixelregion 2 c includes an effective pixel region for generating,amplifying, and reading a signal charge by photoelectric conversion ineach pixel.

The pixel in the pixel region 2 c has a photodiode as a photoelectricconversion unit having a photoelectric conversion function, and aplurality of pixel transistors. The photodiode has a light receivingsurface that receives light incident from the surface 2 a side of theimage sensor 2, and generates a signal charge in an amount correspondingto the light amount (intensity) of the light incident on the lightreceiving surface. The plurality of pixel transistors includes, forexample, MOS transistors that are responsible for amplifying,transferring, selecting, and resetting the signal charges generated bythe photodiode. Note that, regarding the plurality of pixels, thephotodiode and the transfer transistor included in the plurality of unitpixels may have a shared pixel structure configured by sharing the otherpixel transistor.

On the surface 2 a side of the image sensor 2, a color filter and anon-chip lens are formed correspondingly to each pixel via anantireflection film including an oxide film or the like or a planarizingfilm including an organic material, with respect to the semiconductorsubstrate. The light incident on the on-chip lens is received by thephotodiode through a color filter, a planarizing film, or the like.

Examples of the configuration of the image sensor 2 include aconfiguration of a front side illumination type in which the pixelregion 2 c is formed on the surface side of the semiconductor substrate,a configuration of a back side illumination type in which a photodiodeor the like is arranged in reverse and the back side of thesemiconductor substrate is the light receiving surface side in order toimprove light transmission, and a configuration as one chip in whichperipheral circuits of pixel groups are stacked. However, the imagesensor 2 according to the present technology is not limited to thosehaving these configurations.

The substrate 3 is provided on the surface 2 a side with respect to theimage sensor 2, and has the opening 4 for passing light to be receivedby the pixel region 2 c of the image sensor 2. The substrate 3 has arectangular plate-like outer shape as a whole, and has a front surface 3a which is one plate surface and a back surface 3 b which is the otherplate surface on the opposite side. The substrate 3 is, for example, asubstrate formed including a material such as an organic material suchas a plastic or ceramics provided with a wiring layer, electrodes, orthe like.

The substrate 3 is provided parallel to the image sensor 2 and has theopening 4 at the center of the plate surface. The opening 4 has asubstantially rectangular opening shape corresponding to the rectangularouter shape of the substrate 3, and is formed in a penetrating shapefrom the front surface 3 a to the back surface 3 b of the substrate 3.Therefore, the substrate 3 has a frame-like shape as a whole, and therectangular opening 4 is formed by four side portions forming the frameshape. The opening 4 is formed by four inner side surface portions 10having a substantially rectangular shape in a plan view.

With respect to such a substrate 3, the image sensor 2 is provided onthe back surface 3 b side of the substrate 3 with the light receivingsurface facing the front surface 3 a side of the substrate 3 from theopening 4. The image sensor 2 has an outer shape larger than that of theopening 4 of the substrate 3, and is provided so as to close the opening4 from below with respect to the substrate 3. The opening 4 is formed sothat the entire pixel region 2 c of the image sensor 2 is located withinthe opening range of the opening 4 in a plan view.

That is, the pixel region 2 c is formed as a rectangular regioncorresponding to the outer shape of the image sensor 2 in a plan view,and each side forming the outer edge of the pixel region 2 c is locatedinside the inner side surface portion 10 forming the opening 4 in a planview. In other words, in a plan view, there is a distance L1 betweeneach inner side surface portion 10 forming the opening 4 and each sideforming the outer edge of the pixel region 2 c located in the opening 4(see FIGS. 2 and 3).

The metal bump 6 is interposed between the front surface 2 a of theimage sensor 2 and the back surface 3 b of the substrate 3, andelectrically connects the image sensor 2 and the substrate 3 to eachother. The metal bump 6 is a protruding terminal, and for example,electrically connects an electrode formed on the front surface 2 a ofthe image sensor 2 and a wiring layer formed on the back surface 3 b ofthe substrate 3. Due to the presence of the metal bump 6 between theimage sensor 2 and the substrate 3, a gap is formed between the frontsurface 2 a of the image sensor 2 and the back surface 3 b of thesubstrate 3. A dimension L2 of this gap (see FIG. 3) is, for example,about 20 μm.

A plurality of metal bumps 6 is provided, for example, in an array so asto be arranged around the opening 4 at predetermined intervals accordingto the number of electrodes formed on the surface 2 a of the imagesensor 2. The metal bump 6 is, for example, an Au stud bump, a solderball bump, or an Au—Ag alloy bump. The metal bump 6 is covered with theunderfill part 7.

The underfill part 7 is formed including a resin which is a cured fluid,and covers the metal bump 6 existing between the image sensor 2 and thesubstrate 3. The underfill part 7 is formed so as to include a pluralityof metal bumps 6 between an outer circumferential portion of the imagesensor 2 and an inner circumferential portion around the opening 4 ofthe substrate 3, and is a resin sealing part that seals the gap betweenthe image sensor 2 and the substrate 3. The underfill part 7 is providedbetween the image sensor 2 and the substrate 3 in the flip-chipstructure for the purpose of protecting or reinforcing the metal bump 6and the connection portion by the metal bump 6.

The underfill part 7 is a liquid curable resin portion formed by curinga paste-like or liquid resin by baking or the like. In the presentembodiment, the underfill part 7 is of a capillary flow type (capillaryunderfill) formed by flowing a liquid resin having a relatively lowviscosity by using a capillary phenomenon.

As the material of the underfill part 7, for example, a resin materialused as a molding material is used. Specifically, as the material of theunderfill part 7, for example, a thermosetting resin such as an epoxyresin or a thermosetting resin in which a filler containing a siliconoxide as a main component is dispersed is used.

The liquid resin material (for example, thermosetting resin, hereinafterreferred to as “underfill material”) serving as the underfill part 7 isapplied so as to flow by the capillary phenomenon while being dischargedfrom a nozzle of a dispenser, and cover the entire plurality of metalbumps 6 provided in an array, and fill the gap between the image sensor2 and the substrate 3. Therefore, in a plan view, the underfill part 7is formed in a rectangular frame-shaped region corresponding to theshape of the portion where the image sensor 2 and the substrate 3overlap each other, that is, along the opening shape of the opening 4.

The underfill part 7 has a portion that protrudes from the periphery ofthe metal bump 6 due to the surface tension of the underfill material,the wettability of the surface on which the underfill material flows,and the like. Specifically, the underfill part 7 has a surfaceintervening part 7 a existing at the opposite portion of the frontsurface 2 a of the image sensor 2 and the back surface 3 b of thesubstrate 3, and an outer protruding part 7 b, which is a portionprotruding from the surface intervening part 7 a to the outer peripheralside of the image sensor 2.

The glass 5 is an example of the transparent member, and is arectangular plate-shaped member smaller than the substrate 3. By beingprovided on the substrate 3, the glass 5 is provided on the lightreceiving side of the image sensor 2 in parallel with the image sensor 2and at a predetermined interval. The glass 5 is fixed to the surface 3 aof the substrate 3 with an adhesive or the like.

The glass 5 is provided so as to cover the entire opening 4 from abovewith respect to the substrate 3. Therefore, the glass 5 has an externaldimension larger than the opening dimension of the opening 4. Asdescribed above, the glass 5 is provided above the image sensor 2 so asto face the surface 2 a of the image sensor 2 through the opening 4 ofthe substrate 3.

The glass 5 transmits various types of light incident from an opticalsystem such as a lens located above the glass 5, and transmits the lightto the light receiving surface of the image sensor 2 through the cavity8. The glass 5 has a function of protecting the light receiving surfaceside of the image sensor 2, and blocking, together with the substrate 3and the underfill part 7, the intrusion of moisture (water vapor), dust,or the like from the outside into the cavity 8. Note that, instead ofthe glass 5, for example, a plastic plate, a silicon plate thattransmits only infrared light, or the like can be used.

In the solid-state imaging device 1 having the configuration asdescribed above, the light transmitted through the glass 5 passesthrough the cavity 8 and is received and detected by the light receivingelements included in each pixel arranged in the pixel region 2 c of theimage sensor 2.

As described above, the flip-chip structure solid-state imaging device 1having the underfill part 7 has the configuration as below in order tocontrol the flow of the underfill material in the process of forming theunderfill part 7. That is, in the solid-state imaging device 1, thesubstrate 3 has a groove 11 for guiding a fluid that forms the underfillpart 7, that is, an underfill material to the inner side surface portion10 that is a surface portion forming the opening 4 in the direction awayfrom the surface 2 a of the image sensor 2.

The groove 11 is formed as a concave portion with respect to the flatportion of the inner side surface portion 10. That is, the groove 11 isformed by a concave surface 12 on the inner side surface portion 10.Therefore, the inner side surface portion 10 has a flat surface part 13which is a flat surface perpendicular to the plate surface of thesubstrate 3 and the concave surface 12 which is a concave surface withrespect to the flat surface part 13.

The groove 11 is formed along the vertical direction over the entireplate thickness direction of the substrate 3, that is, perpendicular tothe plate surface of the substrate 3. Therefore, the groove 11 has aconstant horizontal cross-sectional shape over the entire platethickness direction (up and down direction) of the substrate 3 by theconcave surface 12, and both the front surface 3 a side and the backsurface 3 b side of the substrate 3 are opened.

In the present embodiment, the groove 11 is formed by a semi-cylindricalconcave curved surface. That is, the concave surface 12 forming thegroove 11 is a semi-cylindrical concave curved surface. Therefore, in aplan view of the substrate 3, the groove 11 forms a semicircular curvedue to the concave surface 12 with respect to the linear flat surfacepart 13.

In the example shown in the drawing, the grooves 11 are provided at twolocations at predetermined intervals in each inner side surface portion10 forming the opening 4. Therefore, the substrate 3 has grooves 11 ateight positions on the surface portion forming the opening 4. In eachinner side surface portion 10, the two grooves 11 are provided in asimilar arrangement mode. Note that the number of grooves 11 included inthe substrate 3 is not limited, and the number and arrangement modes ofthe grooves 11 in each inner side surface portion 10 may be different.

According to the configuration having the groove 11, a part of theunderfill material supplied between the image sensor 2 and the substrate3 passes through the groove 11 in the process of forming the underfillpart 7, and is guided in the direction from the back surface 3 b side ofthe substrate 3 to the surface 3 a side, that is, in the direction awayfrom the surface 2 a of the image sensor 2. The groove 11 guides theunderfill material by capillarity phenomenon. That is, between the imagesensor 2 and the substrate 3, the underfill material that has reachedthe open portion on the lower side of the groove 11 is guided onto theconcave surface 12 in a manner of being sucked up by the capillaryphenomenon.

By guiding the underfill material to the groove 11 as described above, aportion where the underfill material is cured on the concave surface 12of the groove 11 exists as a part of the underfill part 7. Therefore,the underfill part 7 has, in addition to the surface intervening part 7a between the front surface 2 a of the image sensor 2 and the backsurface 3 b of the substrate 3 and the outer protruding part 7 b, aleading out part 7 c having cured underfill material that has beenguided into the groove 11.

From the viewpoint of causing the capillary phenomenon due to the groove11, it is desirable that the diameter D1 (see FIG. 6) of the concavesurface 12 which is a semi-cylindrical concave curved surface has adimension in the range of, for example, 10 to 50 μm. However, the sizeof the diameter of the concave surface 12 is not particularly limited.Furthermore, from the viewpoint of guiding a larger amount of underfillmaterial, it is desirable that the number of grooves 11 is large.

Furthermore, in the configuration for obtaining the guiding action ofthe underfill material by the groove 11, it is desirable that the heightof the metal bump 6 is about 20 μm, for example. Furthermore, it isdesirable that the viscosity of the underfill material is 20 Pa·s orless at room temperature, and more desirably about 10 Pa·s at roomtemperature.

<2. Manufacturing Method of Solid-State Imaging Device According to theFirst Embodiment>

An example of the manufacturing method of the solid-state imaging device1 according to the first embodiment of the present technology will bedescribed with reference to FIGS. 9 to 11.

First, as shown in FIG. 9A, a silicon wafer 20 in which the pixel region2 c corresponding to each image sensor 2 is formed on the surface sideis prepared. The silicon wafer 20 has undergone various processes forforming the image sensor 2. That is, the silicon wafer 20 is asemiconductor wafer in which a plurality of portions serving as theimage sensor 2 in which a pixel group is formed on one plate surfaceside is formed in a predetermined array. In recent years, 8-inch and12-inch wafers are mainly used as silicon wafers 20.

As shown in FIG. 9A, for the silicon wafer 20, a back-grinding (BG)process of cutting the silicon wafer 20 from the back surface 20 b sidein order to make the silicon wafer 20 desired thickness that does notaffect the device characteristics. In the BG process, for example, aback grind foil 21 such as a diamond foil is used, and the silicon wafer20 is polished. Note that, in order to increase the surface roughness ofthe back surface 20 b of the silicon wafer 20, a mirror finishingprocess such as chemical polishing or dry polishing may be performedafter the BG process.

Next, as shown in FIG. 9B, dicing is performed on the silicon wafer 20along a predetermined dicing line. That is, a process of cutting thesilicon wafer 20 so as to divide each portion corresponding to the imagesensor 2 along a predetermined array and individualizing the siliconwafer 20 is performed. In the dicing step, the silicon wafer 20 set on achuck table 22 is divided and individualized by a dicing blade 23 so asto be separated for each image sensor 2. Therefore, the image sensor 2as a large number of sensor chips is obtained.

Subsequently, as shown in FIG. 9C, a process of forming the metal bump 6is performed for each image sensor 2. For example, a wire bonding deviceis used on the electrodes formed on the surface 2 a of the image sensor2, and Au stud bumps as metal bumps 6 are formed. It is desirable thatthe Au stud bump is as small as possible from the viewpoint of costreduction, and is formed at a height of, for example, about 20 μm.

On the other hand, the substrate 3 is created in a substrate creationprocess, which is a process different from the main process flow of theflip-chip structure package including the manufacturing process of theimage sensor 2. As shown in FIG. 10A, in the substrate creation step, anaggregate substrate 25 in which a substrate portion 3A, which is thesubstrate 3 included in the solid-state imaging device 1, istwo-dimensionally connected is created. In the drawing, a portion of theaggregate substrate 25 in which six substrate portions 3A are connectedis shown. For example, an integral aggregate substrate 25 is formedincluding several tens to several hundreds of substrate portions 3A.

The aggregate substrate 25 is a substrate formed including a materialsuch as an organic material such as a plastic or ceramics provided witha wiring layer, electrodes, or the like. Therefore, in the substratecreation process, a base material to be the aggregate substrate 25 isprepared, and a wiring process of providing a wiring layer, electrodes,and the like on the base material is performed.

Next, an opening forming process, which is a process of forming theopening 4 for each substrate portion 3A of the aggregate substrate 25,is performed. In the opening forming process, as shown in FIG. 10B, forexample, the opening 4 is punched by a punching press machine having apunching head 27 which is a jig for punching which is provided so as tobe reciprocally movable by a predetermined drive mechanism 26.

The punching head 27 has a shape corresponding to the opening 4.Therefore, in the punching head 27, the portion acting on the aggregatesubstrate 25 has a flat surface portion 27 a corresponding to the flatsurface part 13 of the opening 4 and a protruding portion 27 b forforming the groove 11. The protruding portion 27 b is a semi-cylindricalridge part protruding from the flat surface portion 27 a correspondingto the flat surface part 13. According to such a punching head 27, theopening 4 having the groove 11 is formed only by punching.

In the punching press machine, in a state where the aggregate substrate25 is set on a stage 28 having an opening 28 a for receiving thepunching head 27, when the punching head 27 moves in a direction ofapproaching a predetermined portion of the substrate portion 3A (seeArrow P1), the substrate portion 3A is punched out and the opening 4 isformed. By the opening forming process, as shown in FIG. 10C, anaggregate opening substrate 25A, which is the aggregate substrate 25 inwhich the opening 4 is formed in each substrate portion 3A, is obtained.

In the opening forming process, the method as below can be adopted.First, a rectangular opening portion is punched and formed in thesubstrate portion 3A of the aggregate substrate 25 by a punching pressmachine having a punching head having a simple rectangular crosssection. That is, the flat surface portion serving as the flat surfacepart 13 in the opening 4 is formed by punching. Thereafter, the groove11 is formed on the flat surface portion forming the punched openingportion by a processing tool such as a drill. According to such amethod, the opening 4 having the groove 11 is formed by a two-stepprocess of a punching step of forming a simple opening portion and acutting step (groove forming step) of forming the groove 11 in the flatsurface portion forming the opening portion.

The aggregate opening substrate 25A is put into the main process of theflip-chip structure package. Then, as shown in FIG. 11A, the imagesensor 2 and the aggregate opening substrate 25A are flip-chip bonded.That is, the image sensor 2 is flip-chip mounted on each substrateportion 3A of the aggregate opening substrate 25A so as to close theopening 4 from the back surface 25 b side which is the back surface 3 bof the substrate 3.

For the flip-chip bonding, a method using a conductive adhesive, amethod using a film-type anisotropic conductive film, an ultrasonicbonding method, a pressure welding method, and the like are used asappropriate depending on the type of the metal bump 6. In the statewhere the image sensor 2 is flip-chip mounted on the aggregate openingsubstrate 25A, the dimension of the gap between the aggregate openingsubstrate 25A and the image sensor 2 is, for example, about 20 μm,corresponding to the height of the metal bump 6.

Next, as shown in FIG. 11B, a process of forming the underfill part 7 isperformed. In this process, the underfill material is supplied to thegap between each image sensor 2 and the substrate portion 3A(hereinafter, referred to as “sensor-substrate gap”) while beingdischarged from a nozzle of a dispenser (not shown). Here, for example,the underfill material is supplied from the outer peripheral side of theimage sensor 2 to the sensor-substrate gap.

The underfill material supplied to the sensor-substrate gap flows intothe sensor-substrate gap due to capillarity phenomenon, covers theentire plurality of metal bumps 6, and spreads so as to fill the gapbetween the image sensor 2 and the substrate 3. Here, on the outerperipheral side of the sensor-substrate gap, the underfill materialspreads like a fillet due to its surface tension or the like andprotrudes from the sensor-substrate gap portion. Furthermore, betweenthe image sensor 2 and the substrate 3, the underfill material that hasreached the open portion on the lower side of the groove 11 is guidedonto the concave surface 12 in a manner of climbing up the groove 11 bythe capillary phenomenon.

Regarding the viscosity of the underfill material, if the viscosity istoo low, the underfill material easily penetrates into the pixel region2 c side, and if the viscosity is too high, penetration in thesensor-substrate gap takes much time. Therefore, as the underfillmaterial, a material of 20 Pa·s or less at room temperature, desirablyabout 10 Pa·s at room temperature is used.

After the underfill material is supplied to the sensor-substrate gap,baking is performed under predetermined temperature conditions in orderto vaporize the solvent contained in the underfill material and solidifythe underfill material. The baking temperature is appropriately setaccording to the underfill material, the solvent contained therein, andthe like. As the baking equipment, a hot plate, an oven, and the likeare appropriately selected and used as needed. By baking, the underfillmaterial is solidified, and the underfill part 7 having the surfaceintervening part 7 a, the outer protruding part 7 b, and the leading outpart 7 c in the groove 11 is formed (see FIG. 4).

Next, as shown in FIG. 11C, the aggregate opening substrate 25A to whichthe image sensor 2 is bonded and the underfill part 7 is formed isinverted and marking is performed. In the marking, for example, uniqueidentification information such as a serial number is attached to eachsubstrate portion 3A of the aggregate opening substrate 25A by lasermarking or the like.

Next, as shown in FIG. 11C, a process of forming a solder ball 29 isperformed at a predetermined portion on the back surface side of eachsubstrate portion 3A of the aggregate opening substrate 25A. The solderball 29 is formed so as to be electrically connected to the wiring partof the substrate portion 3A, for example, through the opening of asolder resist formed on the back surface side of each substrate portion3A.

The solder ball 29 is formed by, for example, a method of placingball-shaped solder in a state where flux is applied to the opening ofthe solder resist, or a method of printing solder paste on the openingof the solder resist using a printing technique, and then reflowing. Thesolder ball 29 serves as a terminal for making an electrical connectionto a circuit board on which the solid-state imaging device 1 is mountedin a predetermined device to which the solid-state imaging device 1 isapplied.

Subsequently, as shown in FIG. 11D, a dicing process is performed inwhich the aggregate opening substrate 25A on which the image sensor 2 ismounted on each substrate portion 3A is divided and individualized inunits of device. In this process, the aggregate opening substrate 25A isdivided by the dicing blade 30 and individualized into a plurality ofdevice elements 31 so that the aggregate opening substrate 25A isdivided into the substrate portions 3A.

Then, the glass 5 is fixed and mounted on the surface 3 a side of thesubstrate 3 with an adhesive or the like on each of the individualizeddevice elements 31. The solid-state imaging device 1 is obtained by theabove manufacturing process. Note that, after mounting the glass 5 oneach substrate portion 3A in the state of the aggregate openingsubstrate 25A, dicing may be performed on the aggregate openingsubstrate 25A.

According to the solid-state imaging device 1 according to the presentembodiment as described above, it is possible to suppress the materialforming the underfill part 7 from flowing to the pixel region 2 c sideof the image sensor 2. Therefore, it is possible to shorten the distancebetween the opening end portion of the opening 4 of the substrate 3 andthe pixel region 2 c, that is, the distance in the horizontal directionbetween the flat surface part 13 forming the opening 4 and an edge ofthe pixel region 2 c facing the flat surface part 13 in a plan view(FIG. 3, interval L1, hereinafter referred to as “distance between theopening end of the substrate and the pixel”). As a result, the imagesensor 2 and the solid-state imaging device 1 can be miniaturized.

In a package structure such as the solid-state imaging device 1according to the present embodiment, in the process of forming theunderfill part 7, it is necessary to keep the distance between theopening end of the substrate and the pixel above a certain level inorder to prevent the underfill material from flowing into the pixelregion 2 c. Here, a configuration in which the groove 11 is not providedin the opening 4 of the substrate 3 is assumed as a configuration of acomparative example. That is, in the configuration of the comparativeexample, a substrate 3X has an opening 4X formed by a flat surface 13Xsuch as the flat surface part 13 as a whole.

In a case of the configuration of the comparative example, if thedistance between the opening end of the substrate and the pixel isinsufficient, for example, as shown in FIG. 12, the underfill materialpenetrates into the pixel region 2 c and the characteristics of theimage sensor 2 deteriorate. In the example shown in FIG. 12, as a partof an underfill part 7X, an inner protruding part 7 d protruding fromthe sensor-substrate gap to the inner peripheral side is formed, andthis inner protruding part 7 d covers the edge of the pixel region 2 c.As described above, in the prior art, from the viewpoint of avoiding thepenetration of the underfill material into the pixel region, it isnecessary to secure the distance between the opening end of thesubstrate and the pixel so that the inner protruding part 7 d does notcover the pixel region 2 c so that there is a limit to theminiaturization of the sensor chip.

On the other hand, the solid-state imaging device 1 according to thepresent embodiment has the groove 11 for guiding the underfill materialin the opening 4 of the substrate 3. With such a configuration, theunderfill material that has penetrated from the application area withrespect to the sensor-substrate gap is guided into the groove 11 by thecapillary phenomenon, and is guided upward by the groove 11. Therefore,the underfill material is suppressed from advancing toward the pixelregion 2 c.

That is, in the solid-state imaging device 1 according to the presentembodiment, the groove 11 of the opening 4 of the substrate 3 controlsthe flow of the underfill material from a direction of advancing towardthe pixel region 2 c (inside) to the direction of climbing up the innerside surface portion 10 of the opening 4, so that the underfill materialis suppressed from protruding from the sensor-substrate gap to the pixelregion 2 c side. Therefore, for example, even if the distance betweenthe opening end of the substrate and the pixel is such that theunderfill material reaches the pixel region 2 c in the configuration ofthe comparative example as shown in FIG. 12, by adopting theconfiguration of the solid-state imaging device 1 of the presentembodiment, it is possible to prevent the underfill material fromreaching the pixel region 2 c. As a result, the distance between theopening end of the substrate and the pixel can be made shorter thanbefore, which can contribute to the miniaturization of the image sensor2.

Furthermore, regarding the shape of the groove 11, in the presentembodiment, the groove 11 is formed by a semi-cylindrical concave curvedsurface. According to such a configuration, it is easy to secure thesurface area of the concave surface 12, and the guiding action of theunderfill material can be effectively obtained. Furthermore, the groove11 can be easily formed by a processing tool such as a drill.

<3. Configuration Example of Solid-State Imaging Device According to theSecond Embodiment>

A configuration example of a solid-state imaging device 51 according toa second embodiment of the present technology will be described withreference to FIGS. 13 to 15. Note that, in the description below, thesame reference numerals will be given to the configurations common tothose of the first embodiment, and the description thereof will beomitted as appropriate. Furthermore, FIG. 13 shows an end view of thecut portion at a position passing through the central portion of agroove 61, as similar to the B-B position passing through the centralportion of the groove 11 in FIG. 4.

The solid-state imaging device 51 of the present embodiment is differentfrom the solid-state imaging device 1 of the first embodiment in thatthe groove 11 of the opening 4 of the substrate 3 is inclined in apredetermined direction.

As shown in FIGS. 13 to 15, in the solid-state imaging device 51 of thepresent embodiment, the groove 61 of the opening 4 of the substrate 3 isinclined in a direction in which the opening width of the opening 4 isnarrowed from the image sensor 2 side to the opposite side, with respectto the plate thickness direction (up and down direction in FIG. 15) ofthe substrate 3.

The groove 61 is formed by a concave surface 62 which is a concaveportion with respect to the flat surface part 13 of the inner sidesurface portion 10. The groove 61 is inclined in a direction from theoutside to the inside from the image sensor 2 side (lower side in FIG.15) to the opposite side (upper side in FIG. 15), that is, a directionin which the opening width of the opening 4 is narrowed, with respect tothe plate thickness direction of the substrate 3.

Specifically, the concave surface 62 forming the groove 61 includes aconcave curved surface part 62 a having a semicircular horizontalcross-sectional shape, and both the front surface 3 a side and the backsurface 3 b side of the substrate 3 are open. In the side sectionalview, the concave curved surface part 62 a makes a straight lineinclined so as to extend from the outside (left and right outside inFIG. 15) which is the outer edge side of the substrate 3 to the inside(left and right inside in FIG. 15) which is the opening part 4 side,from the back surface 3 b side to the front surface 3 a side of thesubstrate 3.

Furthermore, the concave surface 62 forming the groove 61 has a flatsurface part 62 b which is a vertical flat surface at a portion insidethe concave curved surface part 62 a. The flat surface part 62 b isformed at a portion facing the groove 61 in the width direction. Due tothe flat surface part 62 b, the opening area on the lower side (backsurface 3 b side) of the groove 61 is larger than the opening area onthe upper side (front surface 3 a side).

In the method for manufacturing the solid-state imaging device 51 of thepresent embodiment, in the opening forming process of forming theopening 4 of the substrate 3, for example, the punching process offorming the opening portion by a punching press machine as describedabove, and a cutting process (groove forming process) of forming thegroove 61 in the flat surface portion forming the opening portion byusing a processing tool such as a drill are performed. That is, as anopening forming process, after forming a flat surface portion serving asthe flat surface part 13 in the opening 4 by punching, the groove 61 isformed on the flat surface portion forming the punched opening portionby a processing tool such as a drill.

According to the solid-state imaging device 51 according to the presentembodiment as described above, the actions and effects as below can beobtained in addition to the actions and effects obtained by thesolid-state imaging device 1 according to the first embodiment.

That is, in the solid-state imaging device 51 according to the presentembodiment, the groove 61 is inclined in a direction in which theopening width of the opening 4 is gradually narrowed from the lower side(image sensor 2 side) to the upper side (glass 5 side). According tosuch a configuration, by the concave curved surface part 62 a formingthe inclined surface of the groove 61, an action of damming theunderfill material guided upward.

Therefore, it is possible to prevent the underfill material guided bythe groove 61 from climbing up the groove 61 and reaching the surface 3a of the substrate 3. That is, by adjusting the inclination angle of theconcave curved surface part 62 a, it is possible to control the climbingbehavior of the underfill material in the groove 61, and prevent theunderfill material from reaching the surface 3 a of the substrate 3.

Therefore, it is possible to prevent the underfill material fromadhering to the surface 3 a of the substrate 3 which is the supportsurface on which the glass 5 is supported, and it is possible to preventthe underfill material from affecting the mounting structure of theglass 5. Note that, in FIG. 13, as a part of the underfill part 7, aleading out part 7 c formed including the dammed underfill material inthe groove 61 is shown.

<4. Configuration Example of Solid-State Imaging Device According to theThird Embodiment>

A configuration example of a solid-state imaging device 71 according toa third embodiment of the present technology will be described withreference to FIGS. 16 to 19. Note that FIG. 16 shows an end view of thecut portion at a position passing through the central portion of agroove 81, as similar to the B-B position passing through the centralportion of the groove 11 in FIG. 4.

In comparison with the solid-state imaging device 1 of the firstembodiment, the solid-state imaging device 71 of the present embodimentis different in that a lens unit 73 as an optical system including aplurality of lenses 74 and glasses 75 is provided instead of the glass5, and the groove 11 of the opening 4 of the substrate 3 is inclined ina predetermined direction.

As shown in FIG. 16, the lens unit 73 is provided on the surface 3 aside of the substrate 3, and light from a subject is imaged on the imagesensor 2 by the plurality of lenses 74. The lens unit 73 has a supportcylinder 76 formed in a tubular shape, and the lenses 74 and the glasses75 are supported in the support cylinder 76. In the present embodiment,the support cylinder 76 supports three lenses 74 in a state where thethree lenses 74 are stacked in the up and down direction via a spacer orthe like so that the cylinder axis direction is the optical axisdirection. The glass 75 is supported below the lowermost lens 74 and atthe lower end portion of the support cylinder 76. Note that the numberof lenses 74 is not particularly limited.

The lens unit 73 is provided on the substrate 3 so that the optical axisdirection is perpendicular (up and down direction) to the plate surfaceof the image sensor 2. The lens unit 73 is mounted on the substrate 3 ina state where the lower end portion of the support cylinder 76 is fixedand supported on the outer peripheral portion of the surface 3 a of thesubstrate 3 with an adhesive or the like. The glass 75 is an example ofa transparent member as similar to the glass 5 of the first embodiment,and is provided in parallel to the image sensor 2 and at a positionseparated by a predetermined interval with respect to the surface 3 a ofthe substrate 3 so as to cover the entire opening 4 from above, in astate of being supported by the lens unit 73.

In the package structure of the present embodiment, a cavity 78 which isa closed space including the internal space of the opening 4 of thesubstrate 3 is formed by the image sensor 2, the underfill part 7, thesubstrate 3, the glass 75, and the lower end portion of the supportcylinder 76. In such a configuration, light collected by the pluralityof lenses 74 passes through the glass 75 and is incident on the lightreceiving surface of the image sensor 2 through the cavity 78.Furthermore, the solid-state imaging device 71 according to the presentembodiment is used, for example, as shown in FIG. 16, by being mountedon a circuit board 80 including an organic material such as plastic orceramics via a solder ball 79 arranged at a predetermined portion on theback surface 3 b side of the substrate 3.

Next, the groove 81 of the substrate 3 according to the presentembodiment will be described. As shown in FIGS. 16 to 18, in thesolid-state imaging device 71 of the present embodiment, the groove 81of the opening 4 of the substrate 3 is inclined in a direction in whichthe opening width of the opening 4 is widened from the image sensor 2side to the opposite side, with respect to the plate thickness direction(up and down direction in FIG. 18) of the substrate 3.

The groove 81 is formed by a concave surface 82 which is a concaveportion with respect to the flat surface part 13 of the inner sidesurface portion 10. The groove 81 is inclined in a direction from theinside to the outside from the image sensor 2 side (lower side in FIG.18) to the opposite side (upper side in FIG. 18), that is, a directionin which the opening width of the opening 4 is widened, with respect tothe plate thickness direction of the substrate 3.

Specifically, the concave surface 82 forming the groove 81 includes aconcave curved surface part 82 a having a semicircular horizontalcross-sectional shape, and both the front surface 3 a side and the backsurface 3 b side of the substrate 3 are open. In the side sectionalview, the concave curved surface part 82 a makes a straight lineinclined so as to extend from the inside (left and right inside in FIG.18) which is the opening 4 side of the substrate 3 to the outside (leftand right outside in FIG. 18) which is the outer edge side, from theback surface 3 b side to the front surface 3 a side of the substrate 3.

Furthermore, the concave surface 82 forming the groove 81 has a flatsurface part 82 b which is a vertical flat surface at a portion insidethe concave curved surface part 82 a. The flat surface part 82 b isformed at a portion facing the groove 81 in the width direction. Due tothe flat surface part 82 b, the opening area on the lower side (backsurface 3 b side) of the groove 81 is smaller than the opening area onthe upper side (front surface 3 a side).

In the method for manufacturing the solid-state imaging device 71 of thepresent embodiment, in the opening forming process of forming theopening 4 of the substrate 3, as similar to the case of the secondembodiment, for example, the punching process of forming the openingportion by a punching press machine as described above, and a cuttingprocess (groove forming process) of forming the groove 81 in the flatsurface portion forming the opening portion by using a processing toolsuch as a drill are performed. Furthermore, in the main process of thepackage, a process of mounting the lens unit 73 on the substrate 3 isperformed as a process before or after the dicing process for theaggregate opening substrate 25A.

According to the solid-state imaging device 71 according to the presentembodiment as described above, the actions and effects as below can beobtained in addition to the actions and effects obtained by thesolid-state imaging device 1 according to the first embodiment.

That is, in the solid-state imaging device 71 according to the presentembodiment, the groove 81 is inclined in a direction in which theopening width of the opening 4 is gradually widened from the lower side(image sensor 2 side) to the upper side (glass 75 side). According tosuch a configuration, the flow path cross-sectional area of the groove81 gradually increases from the lower side to the upper side, so that itis possible to prevent the underfill material guided in the manner ofclimbing up in the groove 81 from accumulating in the groove 81. Thatis, by adjusting the inclination angle of the concave curved surfacepart 82 a, it is possible to control the climbing behavior of theunderfill material in the groove 81, and prevent the underfill materialfrom accumulating in the groove 81.

Therefore, it is possible to prevent the underfill material fromaccumulating in the groove 81 and solidifying in a state of bulging tothe outside of the groove 81 due to surface tension or the like. Thereis a possibility that the underfill portion that bulges outward from thegroove 81 becomes an inwardly protruding portion in the opening 4 of thesubstrate 3, blocks the light received by the pixel region 2 c throughthe opening 4, and affects the sensor characteristics of the imagesensor 2. Therefore, as described above, the inclination of the groove81 prevents the accumulation of the underfill material in the groove 81,so that the protruding portion of the underfill portion from the groove81 is less likely to be formed, and it is possible to reduce or preventaffection to the sensor characteristics by the underfill portion.

Furthermore, the solid-state imaging device 71 according to the presentembodiment has a configuration in which the lens unit 73 supporting theglass 75 is mounted on the substrate 3 in a state where the lower endportion of the support cylinder 76 is supported on the outer peripheralportion of the surface 3 a of the substrate 3. According to such aconfiguration, for example, unlike the case of the configuration inwhich the glass 5 is mounted so as to cover the opening 4 of thesubstrate 3 as in the solid-state imaging device 1 of the firstembodiment, it is possible to allow the underfill material to reach thesurface 3 a of the substrate 3.

Specifically, as shown in FIG. 19, the glass 75 supported by the supportcylinder 76 supported on the outer peripheral portion of the surface 3 aof the substrate 3 is supported around the opening 4 on the surface 3 aof the substrate 3 in a state of being spaced with a space M1 betweenthe glass 75 and the surface 3 a of the substrate 3. Therefore, theunderfill material can be adhered to the facing portion 3 c of thesurface 3 a of the substrate 3 to the glass 75 (particularly the portionaround the opening 4) without affecting the mounting structure of theglass 75. That is, the underfill material is allowed to reach thesurface 3 a of the substrate 3.

Therefore, for example, as shown in FIG. 19, in the underfill part 7, itis possible to form, in addition to the surface intervening part 7 a,the outer protruding part 7 b, and the leading out part 7 c in thegroove 81, a riding part 7 e formed by cured underfill material that hasreached the surface 3 a of the substrate 3 as an extending portion fromthe leading out part 7 c. Therefore, for example, by intentionallyforming the riding part 7 e by adjusting the inclination angle of thegroove 81, it is possible to guide more underfill material in thedirection away from the pixel region 2 c side, and avoid the underfillmaterial reaching the pixel region 2 c. Note that, even in thesubstrates 3 having the grooves 11 and 61 according to the first andsecond embodiments, by providing the lens unit 73 instead of the glass 5in the solid-state imaging devices 1 and 51, it is possible to form theriding part 7 e in the underfill part 7, and the above-mentioned effectcan be obtained.

<5. Modification of Groove of Substrate>

A modification of the groove of the substrate 3 according to theembodiment of the present technology will be described.

As shown in FIG. 20A, the groove 11A of the first modification has aV-shaped horizontal cross-section. The groove 11A is formed by a pair ofinclined surfaces 91 a having a V-shaped cross-section. That is, thegroove 11A is a concave portion formed in a V notch shape.

As shown in FIG. 20B, the groove 11B of a second modification has ahorizontal cross-sectional shape along a rectangular shape. The groove11B is formed by a bottom surface 92 a having a cross-sectional shapealong a rectangular shape and a pair of side surfaces 92 b facing eachother.

As shown in FIG. 20C, in the third modification, a groove 11C, which isa V-notch-shaped concave portion formed by pair of inclined surfaces 93a, is continuously formed, and each inner side surface portion 10forming the rectangular opening 4 is formed in a triangular wave shape.In this configuration, the portion between the adjacent grooves 11C is aridge portion 93 c having a mountain shape in a plan view.

As shown in FIG. 20D, in a fourth modification, a groove 11D, which is aconcave portion along a rectangular shape formed by a bottom surface 94a and a pair of side surfaces 94 b, is continuously formed, and eachinner side surface portion 10 forming the rectangular opening 4 isformed in a rectangular wave shape. In this configuration, the portionbetween the adjacent grooves 11C is a ridge portion 94 c along therectangular shape in a plan view.

The grooves of each of the modifications shown in FIGS. 20A to 20D areformed perpendicular to the plate surface of the substrate 3 over theentire plate thickness direction of the substrate 3, but the grooves ofthese modifications may be formed so as to be inclined with respect tothe plate thickness direction of the substrate 3 as the groove 61 of thesecond embodiment and the groove 81 of the third embodiment.

As shown in FIG. 21A, a groove 11E of a fifth modification is formed bya concave surface 95 forming a curved line with the left and right outersides as convex sides in a side sectional view. As described above, thegroove according to the present technology may be formed in a curvedshape in the plate thickness direction of the substrate 3. The concavesurface 95 is, for example, a semi-cylindrical concave curved surfacewhose axial direction is the lateral direction (direction along theplate surface of the substrate 3).

As shown in FIG. 21B, a groove 11F of a sixth modification is formed bya concave surface 96 that is curved in the plate thickness direction ofthe substrate 3 in a side sectional view. Moreover, the concave surface96 is inclined in the direction in which the opening width of theopening 4 is narrowed from the lower side to the upper side in the platethickness direction of the substrate 3, as the groove 61 of the secondembodiment.

As shown in FIG. 21C, a groove 11G of a seventh modification is formedby a concave surface 97 that is curved in the plate thickness directionof the substrate 3 in a side sectional view. Moreover, the concavesurface 97 is inclined in the direction in which the opening width ofthe opening 4 is widened from the lower side to the upper side in theplate thickness direction of the substrate 3, as the groove 81 of thethird embodiment.

The above-mentioned actions and effects can also be obtained by thevarious modifications described above. In particular, according to theconfiguration of the sixth modification as shown in FIG. 21B, thesimilar actions and effects as those of the configuration of the secondembodiment can be obtained from the inclination direction of the groove11F. Furthermore, according to the configuration of the seventhmodification as shown in FIG. 21C, the similar actions and effects asthose of the configuration of the third embodiment can be obtained fromthe inclination direction of the groove 11G.

<6. Configuration Example of Electronic Device>

An example of application of the solid-state imaging device according tothe above-described embodiment to an electronic device will be describedwith reference to FIG. 22. Note that, here, an application example ofthe solid-state imaging device 1 according to the first embodiment willbe described.

The solid-state imaging device 1 can be applied to all electronicdevices using a solid-state imaging element in an image capture part(photoelectric conversion part) such as an imaging device such as adigital still camera or a video camera, a portable terminal devicehaving an imaging function, and a copier that uses a solid-state imagingelement in an image reader. The solid-state imaging element may be inthe form of one chip, or may be in the form of a module having animaging function in which an imaging part and a signal processing partor an optical system are packaged together.

As shown in FIG. 22, an imaging device 100 as an electronic deviceincludes an optical part 102, a solid-state imaging device 1, a digitalsignal processor (DSP) circuit 103 which is a camera signal processingcircuit, a frame memory 104, a display part 105, a recording part 106,an operation part 107, and a power supply part 108. The DSP circuit 103,the frame memory 104, the display part 105, the recording part 106, theoperation part 107, and the power supply part 108 are connected to eachother via a bus line 109.

The optical part 102 includes a plurality of lenses, captures incidentlight (image light) from a subject, and forms an image on the imagingsurface of the solid-state imaging device 1. The solid-state imagingdevice 1 converts the light amount of the incident light formed as theimage on the imaging surface by the optical part 102 into an electricsignal in units of pixels, and outputs the electric signal as a pixelsignal.

The display part 105 includes a panel-type display device such as aliquid crystal display panel or an organic electro luminescence (EL)panel, and displays a moving image or a still image captured by thesolid-state imaging device 1. The recording part 106 records the movingimage or still image captured by the solid-state imaging device 1 on arecording medium such as a hard disk or a semiconductor memory.

The operation part 107 issues operation commands for various functionsof the imaging device 100 under the operation of the user. The powersupply part 108 appropriately supplies various power supplies serving asoperation power supplies of the DSP circuit 103, the frame memory 104,the display part 105, the recording part 106, and the operation part 107to these supply targets.

According to the imaging device 100 as described above, in thesolid-state imaging device 1, it is possible to prevent the underfillmaterial from flowing to the pixel region 2 c side of the image sensor2, shorten the distance between the opening end of the substrate and thepixels, and promote miniaturization of the image sensor 2 and thesolid-state imaging device 1, and also miniaturization of the imagingdevice 100.

The description of each of the above-described embodiments is an exampleof the present technology, and the present technology is not limited tothe above-described embodiments. For this reason, it is of course thatvarious modifications can be made according to the design and the like,other than the above-described embodiments, as long as the modificationsdo not depart from the technical idea according to the presentdisclosure. Furthermore, the effects described in the present disclosureare merely examples and are not intended to be limiting, and othereffects may be provided. Furthermore, the configurations of theabove-described embodiments and the configurations of the modificationscan be appropriately combined.

Note that the present technology can adopt the following configuration.

(1)

A solid-state imaging device including:

a solid-state imaging element having a pixel region which is a lightreceiving region including a large number of pixels on a surface sidewhich is one plate surface of a semiconductor substrate;

a substrate provided on the surface side with respect to the solid-stateimaging element and having an opening for passing light to be receivedby the pixel region; and

an underfill part formed including a cured fluid and covering aconnection part that electrically connects the solid-state imagingelement and the substrate,

in which the substrate has a groove for guiding the fluid forming theunderfill part in a direction away from the surface of the solid-stateimaging element, on a surface portion forming the opening.

(2)

The solid-state imaging device according to (1) described above,

in which the groove is formed by a semi-cylindrical concave curvedsurface.

(3)

The solid-state imaging device according to (1) or (2) described above,

in which the groove is inclined in a direction in which an opening widthof the opening is narrowed from a side of the solid-state imagingelement to the opposite side with respect to a plate thickness directionof the substrate.

(4)

The solid-state imaging device according to (1) or (2) described above,

in which the groove is inclined in a direction in which an opening widthof the opening is widened from a side of the solid-state imaging elementto the opposite side with respect to a plate thickness direction of thesubstrate.

(5)

An electronic device including a solid-state imaging device,

the solid-state imaging device including:

a solid-state imaging element having a pixel region which is a lightreceiving region including a large number of pixels on a surface sidewhich is one plate surface of a semiconductor substrate;

a substrate provided on the surface side with respect to the solid-stateimaging element and having an opening for passing light to be receivedby the pixel region; and

an underfill part formed including a cured fluid and covering aconnection part that electrically connects the solid-state imagingelement and the substrate,

in which the substrate has a groove for guiding the fluid forming theunderfill part in a direction away from the surface of the solid-stateimaging element, on a surface portion forming the opening.

REFERENCE SIGNS LIST

-   1 Solid-state imaging device-   2 Image sensor (solid-state imaging element)-   2 a Surface-   2 c Pixel region-   3 Substrate-   4 Opening-   5 Glass-   6 Metal bump (connection part)-   7 Underfill part-   7 a Surface intervening part-   7 b Outer protruding part-   7 c Leading out part-   10 Inner side surface portion-   11 Groove-   12 Concave surface-   51 Solid-state imaging device-   61 Groove-   62 Concave surface-   71 Solid-state imaging device-   73 Lens unit-   81 Groove-   82 Concave surface

What is claimed is:
 1. A solid-state imaging device comprising: asolid-state imaging element having a pixel region which is a lightreceiving region including a large number of pixels on a surface sidewhich is one plate surface of a semiconductor substrate; a substrateprovided on the surface side with respect to the solid-state imagingelement and having an opening for passing light to be received by thepixel region; and an underfill part formed including a cured fluid andcovering a connection part that electrically connects the solid-stateimaging element and the substrate, wherein the substrate has a groovefor guiding the fluid forming the underfill part in a direction awayfrom the surface of the solid-state imaging element, on a surfaceportion forming the opening.
 2. The solid-state imaging device accordingto claim 1, wherein the groove is formed by a semi-cylindrical concavecurved surface.
 3. The solid-state imaging device according to claim 1,wherein the groove is inclined in a direction in which an opening widthof the opening is narrowed from a side of the solid-state imagingelement to the opposite side with respect to a plate thickness directionof the substrate.
 4. The solid-state imaging device according to claim1, wherein the groove is inclined in a direction in which an openingwidth of the opening is widened from a side of the solid-state imagingelement to the opposite side with respect to a plate thickness directionof the substrate.
 5. An electronic device comprising a solid-stateimaging device, the solid-state imaging device including: a solid-stateimaging element having a pixel region which is a light receiving regionincluding a large number of pixels on a surface side which is one platesurface of a semiconductor substrate; a substrate provided on thesurface side with respect to the solid-state imaging element and havingan opening for passing light to be received by the pixel region; and anunderfill part formed including a cured fluid and covering a connectionpart that electrically connects the solid-state imaging element and thesubstrate, wherein the substrate has a groove for guiding the fluidforming the underfill part in a direction away from the surface of thesolid-state imaging element, on a surface portion forming the opening.